Corn gluten feed is a byproduct of corn wet-milling
that is available throughout the country. It is utilized in the
wet form near the site of production, or it is dried to improve
storability and reduce freight charges when shipped. In North
Carolina, dry corn gluten is available to smaller producers from
a variety of sources, and the price is usually 60 to 70% of its
value calculated from the energy and protein levels.

Despite good "book values" for nutrient
content, corn gluten feed has been disappointing as a substitute
for corn and soybean meal in several previous trials when used
as a high percentage of the corn silage or sorghum silage-based
diets for growing calves. The trial reported here explored using
dry corn gluten feed as an alternative supplement to orchardgrass
hay for wintering steer calves.

Materials and Methods

The trial was conducted at the Upper Mountain
Research Station in Laurel Springs, NC. Thirty spring-born Angus
x Simmental steer calves (average initial weight 499 lbs) were
allotted from within weight groups to six pens with two pens per
treatment. The calves had been born at the research site and
were processed using a standard weaning program before starting
the trial.

Calves were fed orchardgrass hay (11.8% crude
protein, 33.5% ADF, .38% Ca and .35% P) and a high calcium mineral
supplement (18.8% Ca, 4.16% P) free choice. Calves received either
#1) 6 lbs per head per day of a standard corn and soybean meal
supplement (13.6% crude protein, 3.2% ADF, .2% Ca and .35% P),
#2) 3 lbs per head per day of the standard supplement and 3 lbs
per head per day of dried corn gluten feed (23% CP, 11.5% ADF,
.02% Ca and 1.16% P) or #3) 6 lbs per head per day of corn gluten
feed. The corn gluten feed was obtained from a major corn processor
and the corn and soybean meal mix was obtained from a local feed
mill. Prices used in the economic analysis were as follows: Hay,
80 $/ton; corn and soybean meal, 175 $/ton; corn gluten feed,
120 $/ton; mineral supplement, 250 $/ton. Cattle were assumed
to be worth $.78/lb initially, and $.70/lb at the end of the trial.

Shrunk weights were taken at the beginning
and end of the 91-day trial. During the 9th week of the trial,
samples of rumen fluid were obtained two hours after feeding using
a stomach tube to evaluate ruminal volatile fatty acid proportions
and ruminal ammonia.

Results and Discussion

Results of the trial are shown in Table 1.
As the level of corn gluten feed increased in the diets, the
growth rate of the calves declined and feed efficiency was reduced.
Neither hay or dry matter intake was changed. When intake of
both the hay and supplement were combined, the calculated protein
level for the three diets was 12.4, 13.9 and 15.6%, and calculated
TDN content was 72.2, 71.9 and 71.7%, for diet 1, 2, and 3 respectively.

There maybe several possible explanations
for the reduced performance of the calves. The protein in corn
gluten feed has a high level of ruminal degradability, so that
it is potentially less valuable that soybean meal. However,
the corn gluten feed was used primarily as an energy source, and
the protein level was allowed to increase, which would probably
offset any reduction in protein quality. It was observed that
there were very high levels of ruminal ammonia with both diets
supplemented with corn gluten feed. The need to detoxify large
amounts of ammonia could have contributed to decreased performance,
although the protein levels were not especially high. The current
trial was not designed to determine why level of production was
reduced; additional experiments will be needed to find strategies
to improve performance with this alternative concentrate.

Economic Analysis.

The expected value of the corn gluten feed was the same as the
amount we paid for the corn and soybean meal ($175/ton). We actually
paid $120/ton, so total feed costs were reduced as the level of
corn gluten feed increased. However, due to the decreased sale
weights, gross return was reduced, resulting in a lower return
over feed cost when level of corn gluten feed was increased.
By setting the return over feed cost of diets containing corn
gluten feed to the same level observed for the standard supplement
a breakeven price for the corn gluten feed was determined. Under
the conditions of this trial, the dry corn gluten feed was worth
$89/ton.

The Bottom Line

Dried corn gluten feed was explored as an
alternative to corn and soybean meal for supplementing growing
steers fed orchardgrass hay. Gain was reduced as corn gluten
feed was substituted for the standard supplement, reducing return
over feed cost given the prices paid for the two supplements.
Additional work needs to be done with dried corn gluten feed
before it can be recommended to producers given current market
prices.

Table 1. Influence of level of corn gluten
feed on the performance of and economic return from steers fed
orchardgrass hay-based diets.